Railway traffic controlling apparatus



July 30, 1940.

H. S. YOUNG RAILWAY TRAFFIC CONTROLLING APPARATUS Filed April 13., 1938Fig. Z.

. INVENTOR Hear Young.

HIS ATI'OYRNEY Patented July 30, 1940 UNITED STATES PATENT OFFICEAPPARATUS Henry S. Young, Wilkinsburg, Pa., assignorj to" The UnionSwitch & Signal Company, Swissjvale, Pa., a corporation of PennsylvaniaApplication April is, 1938,:SerialNo. 201,740

7 Claims. (01; 246- 219):

My invention relates to railway traffic controlling apparatus, andparticularly to apparatus of the type involving a railway switch and asignal for governing traflic movements over the switch. p I

One feature of my invention is the provision of means responsive to atrain approaching the signal for controlling the signal to display afirst and a second indication alternately, andthe provision of meansfordirecting a train movement over the switch in its normal position or itsre Verse position according as the train passes the signal while thesignal is displaying the first or the second indication, respectively.

The apparatus of my invention is an improvement over that disclosed inthe copending applications Serial No. 323,286, filed December 3, 1928,by Lester E. Spray for Multiple control apparatus; and Serial No.118,609, filed December 31, 1936, by John M. Pelikan for Railway trafiicontrolling apparatus. s

I shall describe twoforms of apparatus embodying my invention, and shallthen point out the novel features thereof in claims.

In the accompanying Y drawing, Fig. 1 is a diagrammatic View showing astretch of railway track including a switch, and a signal for governingtrafiic movements over the switch; and Fig. 2 is a diagrammatic viewshowing a stretch of railway track including a switch, and a signal forgoverning .traific movements toward a second signal which governstrafiic movements over the switch.

Similar reference characters refer to similar parts in each 'of theviews. 1

Referring first to Fig. 1, a stretch of railway track is shown includinga switch 3. Switch 3 is operated by a mechanism designated by thereference character 3F, which is in turn controlled by means here shownas electro-magnets 3N. and 3R.

The upper rail of the track, as shown in the drawing, is dividedbyinsulated joints 4 to form sections IT and AII Section IT is providedwith a track circuit including a relay ITR. con

nected across the rails adjacent one end of the section, and section AITis provided with a track circuit including a relay AlTRconnected acrossthe rails adjacent one end of the section. Each of these track circuits,as here shown, includes also the secondary winding Bof a transformer aconnected across the rails adjacent the opposite end of the section.Primary winding 5 of each of the transformers a is energized by currentfrom a suitable source not shown in" the drawing but having terminalsdesignated by the reference characters =BX 1 and CX. Resistors :1 and8are-inc1uded in-track. leads from transformers a and the track relays,respectively, .in accordance with usualpractice with the type 01 5apparatus" shown. 1

A signal ;I is shownadjacent the mutually abutting'ends of sections ITand AIT, so that section Al-T-is, in the rear of signal land section lTis in advance of signal I. Ashere-shown. 10 this signal is of the colorlight type comprising agreen lamp; G, "a yellow lamp Y, and a red lampR. Signal I may, however, be of-any other suitabletype. a

A timing device or mechanism M; having a rotor H which turns about itsaxis in the direction indicated by the arrow, is set into operation whena car or train moving toward: the right as shown in the drawing, whichIshall assume is the eastbound direction, enters section AIT.

Rotor H, when device M is in-operation, rotates contact segments 13 and22 also in the direction indicated by the arrow. As shown inv thedrawing, segment I3 is in engagement with acontact finger .l4. Whendevice M is set into opera- 25 tion, segment 22 will come intoengagement with a contact finger 24 while segment 13 is still inengagement with. finger l4. Segment 13 will next leave finger I4, and,after that, segment 22 will ;leave finger 24. Segment l3 will nextengage a finger H, and segment 22 will afterward engage a finger 23.Segment I3 will then leave finger ll, and, after that, segment 22 willleave finger 23. Segment l3 will then again engage finger M. The cycleof operation just described will then be successively repeated as longas device M is energized. Operated in conjunction with switch 3 areacontact I5 which is closed only when switch 3 is'inthe normal position;a contact l8 which is 40 closed only when switch 3 is in thereversepositicnga contact 20 which is closed when switch 3 is either in itsnormal position or its reverse positiomand a contact which is closedonly between the normal and the reverse positions of switch 3. l I 7With the apparatus in the condition shown in the drawing, that is, withrelay ITR energized and segment l3 in engagement with contact finger Il, switch magnet 3N will be energized for retaining switch 3 in thenormal position in which itis .shown, and green lamp G will be lightedfor directing traific movements ove switch 3 in its normal position.

When a' train enters section AIT, causing de- 5 5 vice M to be operated,red lamp R will be lighted a brief period before lamp G is extinguished,on account of segment 22 engaging contact finger 24 before segment I3 isdisengaged from finger M. The trainman or motorman is thus warned thatthe condition of switch 3 is about to be changed. Lamp G will next beextinguished, and lamp R will remain lighted, until segment 22disengages contact finger 24.

Magnet 3R will become energized when segment l3 engages finger ll,causing switch 3 to be operated to the reverse position, and switch 3causing lamp R to again be lighted while switch 3 is in transit. Whenswitch 3 has reached its reverse position, lamp R will be extinguishedand lamp'Y will become lighted.

As the operation of device M continues, lamp R will again becomelightedbefore lamp Y be comes extinguished, thus warning the trainmanthat the condition of switch 3 is again about to be' changed. 'Lamp Ywill next become extinguished, and lamp R will then again remain lighteduntil segment 22 disengages contact finger 23. i

- Magnet 3N will next become energized when segment l3 again engagesfinger l4, causing switch' 3 to be returned to its normal position,which causes lamp R to again belighted while switch 3 is in transit.When switch 3 has reached the normal position, lamp R will beextinguished, and lamp G will again become lighted. If the car or trainapproaching signal I is to go over switch 3 in its normal position, thetrainman will operate his car or train so that it will enter section ITwhile lamp G is lighted. If, however, the car or train is to 'go overswitch 3 in'its reverse position, the car or train will enter section ITwhile lamp Y is lighted.

Having described in general the operation of the apparatus shown in Fig.1, I shall now describe in detail the operation of the various parts ofthe apparatus.

I-shall assume that a car or train enters section "AIT, causing trackrelay AITR to become deenergized. A circuit will thereby be completedfor operating device M, this circuit passing from a suitable source ofcurrent which may be, and which I shall assume is, the same as thesource which supplies current to primary windings 5 of transformers 1a,the circuit therefore passing from terminal BX, through the front pointof contact 30f relay ITR, contact ll] of relay AITR, and device M toterminal CX. Device M will therefore start turning its segments l3 and22 about its axis. As shown in the drawing, before device M is operated,and for a time after its operation begins, magnet 3N of switch 3 isenergized by a circuit passing from terminal BX through the front pointof contact l2 of relay ITR, contact |3-|4 of device M, and magnet 3N toterminal CX. At the same time, lamp G is lighted by a circuit passingfrom terminal BX, through the front point of contact l2 of relay ITR,contact 13-44 of device M, contact l5'of switch 3, contact 16 of relaylTR,andlamp"G to terminal CX.

After device M starts to rotate, and before contact |3-|4 opens, segment22 will engage contact finger 24,, causing a circuit to be completed for"lighting red lamp R, this circuit passing from terminal BX, throughcontact'22--24 of device M, and lamp R to terminal CX. With lamp R thuslighted contemporaneously with lamp G, the

trainman will know that the condition of switch 3 isaboutto change.After a brief period, contact 13-!4 will open, thereby extinguishinglamp G and deenergizing magnet 3N. Lamp R will, however, remain lightedby the circuit previously traced. After a further brief period of time,contact 22--24 will open, causing lamp R to be extinguished.

Segment l3 will next engage contact finger I1, causing a circuit to becompleted for energizing magnet 3R, this circuit passing from terminalBX through the front point of contactlZ of relay ITR, contact l3ll ofdevice M, and the winding of magnet 3R to terminal CX. With magnet 3Renergized, mechanism 3F will operate switch 3 to its reverse position.As soon, however, as switch ,3 leaves its normal position, lamp R willagain become lighted, by a circuit passing from terminal BX, throughcontact 2| operated in conjunction with switch 3, and lamp R to terminalCX. Lamp R will continue lighted by this circuit until switch 3 reachesits reverse position, whereupon lamp Y will become lighted by itscircuit passing from terminal BX, through the front point of contact [2of relay ITR, contact 'l3l'| of device'M, contact 18 of switch 3,contact IQ of relay ITR, and lamp Y to terminal CX.

If the train is to move over switch 3 in its reverse position, thetrainman will move the train into section IT- while lamp Y is lighted,thereby deenergizing device M-by opening contact 9 of relay I TR at itsfront point. With'relay I TR deenergized, its contact l9 will open thecircuit previously traced for lamp Y, causing lamp Y to becomeextinguished. A third circuit will now be completedforlighting lamp R,passing from terminal BX,-through the back point of contact [2 of relayITR, and lamp R to terminal CX. A circuit will now also be completed forretaining switch 3 'inthe reverse position, this circuit passing fromterminal BX, through the back point of contact 9 of relay ITR, contact20 of switch 3 in the reverse position, and magnet 3R to terminal CX. 7

When the train leaves section IT, the third circuit traced for lamp'Rwill be opened at the back point of contact l2 of relay ITR, causinglamp R to again-become extinguished, and'the circuit for lamp Ypreviously traced will now again become completed at contacts l2 and IQof relay ITR, causing lamp Y to again become lighted.

"I shall next'assume that a second train enters sectionAlT,'causing'relay AITR to again become deenergized. The circuitpreviously traced for device M will now again be completed throughcontact 19 of relay AITR, causing device M to again rotate. Segment 22will engage contact finger 23 before segment l3 disengages contactfinger 11, thereby causing lamp R to become lighted by its circuitpassing from terminal BX, through contact 22' -23 of device M, and lampR to terminal CX. Lamp R now being lighted contemporaneously with lampY, the trainman will know'that the condition of switch 3 is about to bechanged. Segment l3 will next leave contact finger ll, causing lamp Y tobecome extinguished, and segment 22 will then leave contact finger 23,causing lamp R to also be extinguished.

Segment I3 will next engage contact finger l4, causing the circuit formagnet 3N, previously traced, to again be completed. With magnet 3Nenergized, mechanism 3F will operate switch 3 to its normal position.Whileswitch 31s in transit between its reverse and its normal positions,lamp R will again be lighted by the circuit previously traced throughcontact 2| of switch 3. As soon as switch 3'reaches the normalposition,'lamp G will again become lighted by the circuit previouslytraced.

' If the train is to go over switch 3 reversed, the trainman will waituntil lamp Y again becomes lighted before passing signal I. If,howeven-the train is to proceed over switch 3 in the normal position,the trainman will now move his train'into section IT while signal I isdisplaying the green indication. As soon as the train enters section IT,lamp G will be extinguished on account of contacts I2 and I6 of trackrelay ITR becomng opened. The circuit previously traced for magnet 3Nwill also be opened at the front point of contact I2 of relay ITR. Asecond circuit for magnet 3N will, however, now be completed, passingfrom terminal BX, through the backpoint of contact'9 of relay ITR,contact 20 of switch 3 in the normal position, and magnet 3N terminalCX.

When the train leaves section IT, the circuits for lamp R and magnet 3Nwill be opened at the back points of contacts I2 and 9, respectively, ofrelay ITR. The circuits first traced for magnet 3N and lamp G of signalI, through the front point ofcontact I2 of relay ITR, will now againbecome closed, and hence lamp G will be lighted for directing trafficmovements over switch 3 in the normal position.

Referringnow to Fig. 2, the apparatus is here arranged'to provide forlamps Y and G of signal I to be alternately lighted due to the alternateclosing of contacts I3-I4 and I3-II of device M as in Fig. 1, but theoperation of switch I will not occur until the train enters section IT.A

second signal 2 is here provided to inform the trainman when switch 3 isin the position corre sponding to the indication displayed by signal Iwhen his train entered section IT. 7

In Fig. 2, a slow release relay ITPR is energized by a circuit includinga front contact of track relay ITR. i A normal stick relay WNRcontrolled by contact I3-I4 of device M and a reverse stick relay WRRcontrolled by contact I3-I'I of d vice M are provided for controllingthe operation of switch 3 and signal 2. n Manually controllable pushbutton circuit controllers designated by the reference characters NPBand RPB, are provided for at times energiz-' ing relays W'NR and WRR,respectively.

Operated in conjunction with switch 3 in Fig. 2 is a contact 31 which,while the switch is in its normal position only, controls a givencircuit portion, and which, while the switch is in its reverse positionor between the normal and reverse positions, controls a second circuitportion. Also operated in conjunction with switch 3 in Fig; 2 is asecond contact 38 which controls a third circuit portion while theswitch is in its normal position or between its normal and reversepositions, and which controls a fourth circuit portion when the switchis in its reverse position only. a

With the parts of the apparatus of Fig. 2 in the condition in which theyare shown in the drawing, lamp G of signal I is lighted by a circuitpassing from terminal BX, through contact I3-I4 of device M, front pointof contact 25 of .'relay ITR, and lamp G to terminal CX. Relay ITPR isenergized by its circuit passing from terminalBX, through contact 21 ofrelay ITR, and the Winding of relay ITPR to terminal CX. Relay WNR isenergized by its stick circuit passing from terminal BX, through contact3| of relay WRR, contact 32 of relay WNR, and the winding ofrelay WNR toterminal CX. With relay WNR energized, magnet 3N of switch 3 isenergized -:byits! switch circuit passing from terminal BX, throughcontact 36 of relay WNR, and the winding ofmagnet 3N to terminal CX.With switch3in the normal position and with relay WNR energized, lamp Gof signal 2 is lighted by a circuit passing from terminal BX, throughcontact .31 of switch 3 in the normal position, front point of contactof relay WNR, and lamp G to terminal CX.

I shall assume that, with the parts of the apparatus of Fig. 2 in thecondition just described, "a train enters section AIT, causing relayAITR to become deenergizedx-Device M will therefore be energized by itscircuit passing from terminal BX, throughcontact 9a of relay ITR,contact IU of, relay AITR, and device M-to terminal CX.

Before contact I3-.I4 opens, contact 22-+24 of device M will close, thuscausing lamp R to become lighted by its circuit which is the same as thecorresponding circuit previously traced in Fig 1; Lamp 1?. willtherefore be lighted for a brief period of-time contemporaneously withlamp G, and hence the trainman will know that the condition ofthe'apparatus. is about to change. After a further brief'period of time,contact I3--I4 will open, causing lamp G to be extinguished. r'As deviceM turns still further, contact -2224 willopen,.thus extinguishing lampR.

Segment I3 of device M will next engage contact finger I1, causing acircuit to be completed for lighting lamp Y, passing from terminal BX,through contact I3-II of device M, front point of contact 25' of relayITR, and lamp Y to terminal ,CX;

I shall further assumethat the train is to go over switch3 in'the normalposition. The train-j man will therefore not pass signal I while lamp Yis lighted...'

Contact'22- -23'will close before contact I3I'I of device M opens,causing lamp R to become lighted by the circuit previously traced inconnection with Fig. l through contact 2223. Lamp R is there-forelighted contemporaneously with lamp Y,"showing the trainman that thecondition of the apparatus is again about to change. After a briefperiod, contact I3II will open, causing lamp Y to become extin guished,and, after a further period of time, contact 2223 of device M will open,causing lamp R to again becomeextinguished.

Contact I3'I I of device M will next become closed, completing thecircuit previously traced for lamp 'G. With lamp G now lighted, thetrainman will advance his train into section IT,

causing relay I TR to become deenergized. Relay ITR, upon becomingdeenergized,-opens the circuit for lamp G at the front point of itscontact 26, causing lamp G to become extinguished, and, through itscontact 28, closes a third circuit for lampR of signal I, causing thislamp R to again be lighted. 'I'he'circuit for relay ITPR is alsoopenedat contact-21 of relay ITR, but, on account of relay ITPR beingslow releasing, a pick-up circuit will be closed momentarily forenergizing relay WNR,'this circuit passing from terminal BX, throughcontact I3I4 of device M, back point of contact 26 of relay ITR,, frontpoint of contact-39 of'relay ITPR, and the winding of relay WNR toterminal CX. Since relay WNR is already energized by its stick circuitpreviously traced, there will be no change in the condition of relay WNRor of lamp G of signal 2. After a brief period of time, relay ITPR willpermit its contact 30'to open at its front point, thereby breaking thepick-up circuit previously traced for relay WNR through this contact.

When the train leaves section IT, relay ITR w l again become energized,thus again completing the circuit for lamp G of signal I, causing lamp Gto again become lighted. With relay ITR again energized, relay ITPR willalso again become energized by its circuit previously traced.

I shall next assume that a second train enters section A IT, causingrelay'AlTR to again become deenergized and device M to again becomeoperated. After a time, lamp Y of signal I will again become lighted aspreviously described.

'I shall now further assume that the train is to go over switch 3 in thereverse position. The trainman will therefore move his train intosection IT while lamp Y of signal I is lighted, thus causing lamp Y tobe extinguished and lamp R of signal I to again be lighted. A circuitwill now be completed for energizing relay WRR, this circuit passingfrom terminal BX, through contact l3-l'| of device M, back point ofcontact of relay ITR, front point of contact 29 of relay ITPR, and thewinding of relay WRR to terminal CX. Relay WRR, upon becoming energized,opens its contact 3| in thestick circuit for relay WNR, causing relayWNR to become deenergized. The stick circuit for relay WRR then becomesclosed, passing from terminal BX. through contact 33 of relay WNR,contact 34 of relay WRR, and the winding of relay WRR to terminal CX.

With relay WNR deenergized, the circuit previously traced for lamp G ofsignalZ is open at the front point of contact 40 of relay W'NR, causinglamp G to be extinguished. When relay WNR becomes deenergized, lamp R ofsignal 2 becomes lighted by a circuit passing from terminal BX, throughcontact 31 of switch 3 in the normal position, back point of contact 40of relay WNR, and lamp R of signal 2 to terminal CX.

With relay WNR deenergized, the circuit for magnet 3N of switch 3 isopen at contact 36 of relay WNR, and, with relay WRR energized, thecircuit for magnet 3R is now closed, passing from terminal BX, throughcontact 35 of relay WRR, and the winding of magnet 3R to terminal CX.With magnet 3R energized, switch mechanism 3F will move switch 3 to thereverse position. As soon as switch 3 leaves the normal position, asecond circuit will be completed for lighting lamp R of signal 2, thiscircuit passing from terminal BX, through contact 31 of switch 3 in anintermediate position, contact 38 of switch 3 in an intermediateposition, and lamp R to terminal CX. The circuit first traced for lampR- of signal 2 is now open at the normal position of contact 31 ofswitch 3.

As soon as switch 3 reaches the reverse position, the second circuit forlamp R will be opened at contact 38 of switch 3, and a circuit will becompleted for lighting lamp Y of signal 2, this circuit passing fromterminal BX, through contacts 31 and 3B of switch 3 both in the reverseposition, front point of contact 39 of relay WRR, and lamp Y of signal 2to terminal CX. With lamp Y of signal 2 lighted, the trainman willbecome energized by its circuit previously tracedthrough contact 21 ofrelay ITR. I shall again assume that a train passes signal I while lampY of signal I is lighted, but that the trainman finds that he should goover switch 3 in the normal position instead of in the reverse position.He will therefore depress circuit controller NPB, completing a secondpick-up circuit for relay WNR, this circuit passing from terminal BX,through controller NPB, back point of contact of relay ITPR, and thewinding of relay VVNR to terminal CX. Relay WNR, upon becomingenergized, opens the stick circuit for relay WRR at its "contact 33,causing relay WRR to become deenergized. A stick circuit will then becompleted for relay WNR as previously traced.

As soon as switch 3 again reaches the normal position, the circuitpreviously traced through contacts 31 and 38 of switch 3 in theintermediate position for lighting lamp R of signal 2 will be open, andhence lamp R will be extinguished. LampG of signal 2 will now again belighted by the circuit previously traced.

From the foregoing description and the accompanying drawing, it followsthat apparatus embodying my invention provides means controlled by anapproaching train for operating a switch to the normal and reversepositions, and for selectively retaining a switch in, or operating itto, the normal or the reverse position according as the train passes agiven signal while the signal is displaying a first or a secondindication, respectively. This system is particularly adapted for use onelectric railways having cars which can start and stop quickly, but mayalso be modified, in a manner whichwill be obvious to persons skilled inthe art, for use with heavier trains.

Other schemes have been provided. for controlling the position of aswitch in accordance with the speed at which a train approaches. Anadvantage of the present scheme is that the position of the switch doesnot depend on the speed at which a train approaches. A car or train mayeven stop on the section in the rear of the signal without causing anydifiiculty in the operation of the apparatus.

Although I have herein shown and described onlytwo forms of railwaytrafiic controlling apparatus embodying my invention, it is understoodthat various changes and modifications may be made therein within thescope of the appended claims Without departing from the spirit and scopeof my invention.

Having thus described my invention, what I claim is: I

1'. In combination, a stretch of railway track including a switch, afirst and a second contact, means set into operation by a train upon itsarrival on said track a given distance from said switch for alternatelyclosing said first and second contacts, means controlled by said firstcontact in its closed position for operating said switch to a givenextreme position, means controlled by said second contact in its closedposition for operating said switch to the reverse position, a signalcapable of displaying a first or a second indication, means controlledby said first contact and by said switch in said given extreme positionfor energizing said signal to display its first indication, meanscontrolled by said second contact and by said switch in the reverseposition for energizing said signal to display its second indication,and means controllable by said train upon its arrival on said track asecond given distance from said switch for discontinuing themeanscontrolled by ,said one contact'in the condition for retaining saidswitch in the corresponding position. I

2. In combination, a stretch of railway track including a switch,asignal capable of displaying a first or a second indication fordirecting traflic movements over said switch in the normal or thereverse position respectively, a first and a second contact, meansresponsive to trafiic conditions on said track for alternately closingsaid first and second contacts while said track is occupied within agiven distance in the rear of said signal, means responsive to saidfirst contact in its closed position for'operating said switch to thenormal position and for then operating said'signal to display its firstindication, means responsive to said second contact in its closedposition for operating said switch to the reverse position and for thenoperating said signal to display its second indication, and meanscontrollable by a train upon passing said signal for discontinuing thealternate closing of said first and second contacts while one of saidcontacts is closed and thereby leaving said one contact closed forretaining said switch in the corresponding position.

3. In combination, aistretch of railway track including a switch, asignal capable of displaying a first or a second or a third indication,a first and a second contact and also a third and a fourth contact,means responsive to traffic conditions on said track for repeatedlyclosing and then opening each of said contacts in the order named whilesaid track is occupied within a given distance in the rear of saidsignal so that the first contact becomes closed and then the secondcontact becomes closed and next the first contact opens and later thesecond contact opens and then the third contact closes and later thefourth contact closes and next the third contact opens and then thefourth contact opens and this cycle of operation then begins again,means responsive to said first contact in its closed position foroperating said switch to the normal position and for then operating saidsignal to display said first indication, means responsive to said secondcontact in its closed position for operating said signal to display saidthird indication, means responsive to said third contact in its closedposition for operating said switch to the reverse position and for thenoperating said signal'to display said second indication, meansresponsive to said fourth contact in its closed position for operatingsaid signal to display said third indication, and means controllable bya train upon passing said signal for discontinuing the cycle ofoperation of said contacts while either said first or said third contactis closed for retaining said switch in the corresponding position.

4. In combination, a stretch of railway track including a switch, asignal capable of displaying a first or a second indication fordirecting traffic movements over said switch in its normal or itsreverse position respectively, a second signnal in the rear of saidfirst signal capable of displaying corresponding first and secondindications for directing traffic movements toward said first signal, afirst and a second contact, means responsive to traffic conditions foralternately closing said first and second contacts'when a train iswithin a given distance in the rear of said second signal, meansresponsive to said first contact in its closed position for energizingsaid means responsive to said second contact in; its closed position forenergizing said second signal to display its second indication, meanscontrollable by a train upon passing said second signal 5 fordiscontinuing the alternate closing of said first and second contactswhile one of. said contacts is closed and thereby leaving said onecontact closed, and means responsive to a train on said track uponpassing said second signal and controlled by said first and secondcontacts for operating said switch to its normal or reverse positionrespectively according as said first or second contact remains closedand for energizing said first signal to display its first or secondindication according as said first or said second contact remainsclosed.

5. In combination, a stretch of railway track including a switch, asignal capable of displaying a first or a second indication fordirecting traffic movements over said switch in its normalor its reverseposition respectively, a second signal in the rear of said first signalcapable of displaying corresponding first and second indications fordirecting traffic movements toward said first signal, a first and asecond contact,'means responsive to traffic conditions for alternatelyclosing said first and second contacts when a train is within a givendistance in the rear of said second signal, means responsive to saidfirst contact in its closed position for energizing said second signalto display its first indication, means responsive to said second contactin its closed position for energizing said second signal to display itssecond indication, means controllable by a train upon passing saidsecond signal for discontinuing the alternate closing of said first andsecond contacts while one of said contacts is closed and thereby leavingsaid one contact closed, a slow release relay, a circuit for energizingsaid slow release relay which becomes opened when a train passes saidsecond signal, means controlled by a front contact of said slow releaserelay and by a train on said track upon passing said second signal foroperating said switch to its normal or reverse position according assaid first or second contact remains closed, manually controllable meanscontrolled in part by a back contact of said slow release relay foreffecting operation of .said switch to its normal and reverse positions,and means operated in conjunction with'said switch for energizing saidfirst signal to display its first or second indication according as saidswitch occupies its normal or its reverse position.

6. In combination, a stretch of railway track including aswitch, asignal capable ofdisplaying a first or a second indication for directingtrafiic movements to proceed toward said switch, a first and a secondcontact, means responsive to a train within a given distance in the rearof said signal for alternately closing said first and second contacts,means controlled by said first contact in its closed position foroperating said switch to the normal position and for then energizingsaid signal to display its first indication, means controlled bysaid'second contact in its closed position for operating said switch tothe reverse position and for then energizing said signal to display itssecond indication, and means controllable by a train upon proceedingfurther for discontinuing the alternate closing of said first and secondcontacts while one of said contacts is closed and thereby leaving saidone contact closed for returning said switch in the correspondingposition.

second signal to display its first indication,

'7. In combination, a stretch of railway-track said switch to a firstextreme position and for including a switch, a first and a'second'contact, then energizing said signal 'to display its first meanscontrolled by a train approaching" said indication and controlled bysaid second contact switch for alternately closing said first andsecwhen closedfor operating said switch to its other end contacts, asignal capable of displayinga extreme position and for then energizing.said 5 first or a second indication, and means'controlled signal todisplay its second indication.

by said first contact when'closed for operating HENRY S. YOUNG.

